This invention relates generally to a combination locking sheath and knife, and more specifically, a knife that can be easily extracted from the sheath for use.
When carrying a fixed-blade knife, it is typically desired that the knife blade be retained within a sheath or scabbard at all times the knife is not in use. Furthermore, since fixed-blade knives are typically carried and used in dynamic activities such as hunting, SCUBA diving, sky diving and other such activities, it is desirable to have the fixed-blade knife secured to the sheath such that the knife will not be lost, and more importantly that the knife will not inadvertently exit the sheath and injure the carrier or others in close proximity and will not damage any gear.
There do remain instances, however, where extraction of the knife from the sheath very quickly and easily is of paramount importance. Such instances may include, for example, a sky diver having to cut himself free from a tangled parachute, or a SCUBA diver getting entangled in fishing lines from a passing boat.
The need for securing a knife to a sheath was recognized long before any patent system was developed, and was originally accomplished by simply tying the knife to the sheath with a leather strap. The leather strap was eventually given a snap to make it faster and more user-friendly.
In more recent years, locking mechanisms have included such ideas as a rubber ring that is stretched over the handle of the knife, which is particularly common in SCUBA diving knives, as well as spring biased levers, latches, or buttons. The spring biasing devices have been located on either the knife handle or on the sheath. In either case however, the spring-biased device springs back to its original position upon releasing the knife from the sheath. In the case where the spring-biased device is on the knife, there exists potential for the spring-biased device to interfere with the interaction between the user's hand and the knife such that comfort, safety, and usefulness are hindered. It is also typical for the spring-biased device to be physically located in such a place and manner that one or more fingers are required to perform dexterous tasks in order for the locking mechanism to be disengaged.
What is needed, therefore, is a knife that can be securely locked into a sheath when not in use, yet requires no additional action other than gripping the knife in a normal use position to release the locking mechanism, without sacrificing comfort, safety, and usefulness.